Stunning intensity of 2007 Kansas tornado examined

Tuesday

Dec 30, 2008 at 12:01 AMDec 30, 2008 at 12:13 PM

WICHITA, Kan. -- The first in-depth study of the 2007 tornado that destroyed a Kansas town has uncovered new details and raised questions about one of the strongest and most dramatic tornado outbreaks ever recorded.

WICHITA, Kan. -- The first in-depth study of the 2007 tornado that destroyed a Kansas town has uncovered new details and raised questions about one of the strongest and most dramatic tornado outbreaks ever recorded.

"There are a lot of things in that storm that made me go, 'Wow,' " said Les Lemon, a co-author of the study. "Most meteorologists will see this kind of storm once in their lifetime," said Lemon, a research-associate meteorologist with the Cooperative Institute for Mesoscale Meteorological Studies at the University of Oklahoma.

A tornado 1.7 miles wide and measuring EF-5 on the Enhanced Fujita scale virtually wiped Greensburg, Kan., from the map on the night of May 4. It killed 11 people and injured more than 50.

It was one of 22 tornadoes that touched down in southern and central Kansas from the same thunderstorm complex that night and early the next morning.

That's more tornadoes than initially thought, said Mike Umscheid, co-author of the study and the meteorologist who issued the "tornado emergency" warning that night for the Dodge City branch of the National Weather Service. A handful of small tornadoes rotating around larger twisters initially went unnoticed.

Four of the tornadoes were especially large.

The Greensburg tornado's peak winds were estimated at more than 200 mph, based on damage in downtown Greensburg.

The tornado that struck Moore, Okla., and other suburbs of Oklahoma City on May 3, 1999, was labeled perhaps the strongest tornado ever recorded. But research shows that the Greensburg tornado had EF-3 or stronger damage in a track at least a mile wide, at least double the width of the Moore tornado.

"When you compare the two damage paths, there's really not much comparison," Umscheid said.

After destroying 95 percent of Greensburg, the tornado continued north, then curled west and looped back around, nearly striking the town a second time before lifting.

By then, a second large tornado was on the ground a few miles to the northeast. That second twister -- eventually dubbed the Trousdale tornado -- grew to more than two miles wide and EF-3 strength.

While it was on the ground, a third tornado touched down and moved north-northeast on a parallel path a few miles to the east. Called the Hopewell tornado, it killed Alex Giles on his farm near Hopewell and grew to 1.3 miles wide and EF-3 strength.

The Trousdale and Hopewell tornadoes were on the ground at the same time for nearly half an hour.

As the Hopewell tornado weakened, another large tornado touched down and tracked northeast, just east of Macksville. Stafford County Deputy Sheriff Robert "Tim" Buckman was killed when the tornado struck his patrol car on Rt. 50.

In addition to the number of tornadoes that night, their strength also was remarkable. The Greensburg and Trousdale tornadoes were so intense that the weather service's radar in Dodge City detected vortex holes in them -- something radar had never done, Umscheid said.

A vortex hole "is what you would see in the eye of a hurricane," he said. Such holes form when winds are rotating so rapidly that they pull debris and even large raindrops from the center of the storm, Umscheid said.

The Trousdale tornado's vortex hole was about 2 miles in diameter -- not much smaller than the eye of Hurricane Charley, a Category 4 storm that hammered Florida in 2004.

The tornado outbreak figures to be a teaching tool for meteorologists around the world.

"If we see signs like this again, I would feel pretty confident in using pretty powerful language in my warnings," Umscheid said.